In performing knee surgery, it is of the utmost importance to avoid or to at least minimize damage to ligaments, tendons, muscles, nerves and other portions of the soft tissue while gaining access to and performing surgical procedures on various portions of the bone structure of the knee. Heretofore, retractors have been utilized in performing knee surgery so as to maximize access to the bone structure intended for osteotomy procedures while, at the same time, providing maximum protection for various soft tissue members. During the knee surgery, an appropriate incision is made along the forward area of the knee joint with the skin and flesh being parted to provide access to the joint. The flesh and the collateral ligaments are typically pulled or retracted laterally to expose the joints and held in this position by a hand held instrument, often referred to as a retractor. These hand-held retractors are held either by the surgeon or his assistant to maintain exposure to the joint to permit surgery to be performed.
In the past, various patents have issued relating to such collateral ligament retractors. For example, U.S. Pat. No. 4,520,797, issued on Jun. 4, 1985 to T. D. Petersen, discloses a collateral ligament retractor for use in knee surgery. This retractor includes a member having a cupped arcuate finger for insertion into the knee joint along and partly around the tibial plateau and a curved portion extending from the finger outwardly along the ligament, then extending back substantially in the same direction as the finger and including a downwardly extending pivoted elongated arm extending to a position behind the knee above the calf. A second member of similar design, but larger to accommodate the everted patella, is positioned around the opposite ligament. A tension member, such as a coil spring, is connected to the outer end of the arms of the members for biasing them toward one another to hold the ligaments in a retracted position.
U.S. Pat. No. 5,334,194, issued on Aug. 2, 1994 to W. W. Mikhail, teaches a collateral ligament retractor for use in performing knee surgery which includes a handle having a flat portion, an integral support section extending from the flat portion of the handle and following a curved path downwardly, and a tip extending from the integral support section and following a curved path in a reverse direction from that of the integral support section. The tip terminates in an end angled upwardly toward and below the plane defined by the horizontally positioned flat portion. The tip has edges tapering toward each other as they approach the end. U.S. Pat. No. 5,397,330, to the same inventor, describes a variation on the ligament retractor of U.S. Pat. No. 5,334,194. U.S. Pat. No. 5,397,330 is particularly utilized in association with posterior cruciate ligament surgery. U.S. Pat. No. 5,380,331, issued on to the same inventor on Jan. 10, 1995, describes a lateral patellar retractor for use in performing knee surgery which has a similar structure in which the support and the prongs are sized to permit the prongs to engage the shelf of the lateral tibial condyle while the support is engaging soft tissue. U.S. Pat. No. 5,308,350, issued to the same inventor on May 3, 1994, shows a femoral distractor for use in knee surgery which includes a rod for insertion in the medullary canal of the femur and a detachable handle assembly. The detachable handle assembly permits the leg of a patient to be moved between positions of extension and flexion without the necessity of removing the rod from the medullary canal.
One of the major problems with these prior art ligament retractors is the fact that they are formed of a rigid steel material and utilize complicated spring-type mechanisms. As such, after each surgery, all of the items involved with the retractor assembly must be sterilized by autoclaving. As a result, the instruments are relatively expensive items. Since they are not disposable, additional costs are associated with the maintenance of such equipment. In other circumstances, since the instruments must be sterilized, they may, on occasion, be unavailable during surgery. Since each of the items described in these prior art patents are relatively expensive items, it is unlikely that the hospital will keep a large supply of such retractors available.
In other circumstances, the spring-type mechanism associated with these retractor assemblies may be inadequate in providing the proper tension to the surfaces being retracted. Since pre-tensioned coil springs are used by the prior art, they may not exert the proper tension required. Furthermore, during the surgical procedures, these prior art retractors do not provide a technique whereby the surgeon can increase the amount of tension applied to the collateral ligament retraction or to decrease the amount of tension. Also, because of the relatively complex nature of these retractor assemblies, the surgeon will require a great deal of time to be completely familiar with the proper operation of such items.
It is an object of the present invention to provide a ligament retractor assembly which is disposable.
It is another object of the present invention to provide a ligament retractor assembly which can assure proper and adjustable tensioning, in an easy manner, during the course of the surgical procedure.
It is another object of the present invention to provide a ligament retractor assembly which does not require sterilization or autoclaving subsequent to surgery.
It is a further object of the present invention to provide a collateral ligament retractor assembly which is easy to use, relatively inexpensive, and easy to manufacture.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.